| 1. |
- Abd Mutalib, Nor Fariza, et al.
(författare)
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A Prediction for the Conversion Performance of H2S to Elemental Sulfur in an Ionic-Liquid-Incorporated Transition Metal Using COSMO-RS
- 2022
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Ingår i: CHEMISTRY-SWITZERLAND. - : MDPI AG. - 2624-8549. ; 4:3, s. 811-826
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the conversion performance of hydrogen sulfide (H2S) to elemental sulfur in ionic-liquid-incorporated transition metals (ILTMs) is predicted using a conductor-like screening model for realistic solvents (COSMO-RS). The predictions were made via the establishment of a correlation between the conversion performance and solubility of H2S in ionic liquids (ILs). All molecules involved were optimized at the DFT/TZVP/M06 computational level and imported on the COSMOtherm program at equimolar conditions. For validation purposes, the solubility of ILs was predicted at 1 bar pressure. Simple regression analysis was used to establish a relationship between the solubility and conversion performance of H2S. The results indicate that the solubility prediction of ILs is accurate (R-2 = 93.40%) with a p-value of 0.0000000777. Additionally, the conversion performance is generally found to be dependent on the solubility value. Furthermore, 1-butyl-3-methylimidazolium chloride [bmim][Cl] was chosen as the base IL for incorporating the transition metal, owing to its solubility and selectivity to H2S. The solubility trend of ILTMs is found to follow the following order: [bmim][NiCl3] > [bmim][FeCl4] > [bmim][CoCl3] > [bmim][CuCl3]. According to the viscosity measurements of ILTMs, [bmim][NiCl3] and [bmim][FeCl4] exhibited the highest and lowest viscosity values, respectively. Therefore, [bmim][FeCl4] is a promising ILTM owing to its higher solubility and low viscosity for the application studied.
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| 2. |
- Ahmad, Tausif, et al.
(författare)
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Controllable phytosynthesis of gold nanoparticles and investigation of their size and morphology-dependent photocatalytic activity under visible light
- 2020
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Ingår i: Journal of Photochemistry and Photobiology A. - : Elsevier. - 1010-6030 .- 1873-2666. ; 392, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Plants mediated synthesis of gold nanoparticles (AuNPs) containing desired characteristics for their suitable potential applications has been a challenging task, which is causing a major hindrance towards its commercialization. Therefore, herein phytosynthesis of AuNPs with required size and morphology has been achieved through manipulating the reaction conditions including reaction temperature and volume of Elaeis guineensis leaves (EGL) extract. Furthermore, photocatalytic potential of EGL mediated AuNPs having different size and shape has also been explored for the removal of methylene blue (MB) under visible light irradiation. The reaction temperature and volume of EGL strongly influenced the size and morphology of AuNPs, which are directly associated with the photocatalytic activities. The experimental results revealed that predominantly spherical and ultra-smaller size AuNPs with particle size of 16.26 ± 5.84 nm, formed at 70 °C showed the highest removal efficiency up to 92.55 % in 60 min. This highest photocatalytic activity of AuNPs could be attributed to the availability of higher number of low-coordinated gold (Au) atoms in the MB aqueous solution, which might have boosted the adsorption of the MB on the surface of particles and accelerated the degradation phenomenon. The proposed photocatalytic degradation mechanism of AuNPs for MB was also explained. The highly photoactive EGL mediated AuNPs with controllable morphology and size could be an advance step in future in chemical and biomedical applications.
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| 3. |
- Idris, Alamin, et al.
(författare)
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Investigation on particle properties and extent of functionalization of silica nanoparticles
- 2020
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 506
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Tidskriftsartikel (refereegranskat)abstract
- Quantification of the extent of functionalization on silica nanoparticle surface is crucial in a variety of applications. This work aims to evaluate particle properties and extent of functionalization on silica nanoparticles synthesized under acidic and basic conditions via co-condensation of tetraethyl orthosilicate with 3-aminopropyltrimethoxysilane in the sol-gel process. The silica nanoparticles properties were analyzed via field emission scanning electron microscope, transmission electron microscopy, dynamic light scattering, and Brunauer-Emmett-Teller methods; whereas, the extent of functionalization was evaluated using Fourier transform infrared spectroscopy, X-ray photoelectron spectrometer, and thermogravimetric analyzer. Results showed that the functionalized silica nanoparticles have a lower tendency to agglomerate and highly monodispersed as compared to unfunctionalized. The surface areas of acid and base-catalyzed nanoparticles were obtained as 618.8 and 514.7 m2/g, respectively. FTIR spectra, XPS scans, and TGA curves confirmed the presence of alkyl and amine functional groups on the functionalized surfaces. The extent of functionalization (N/Si) was obtained as 0.296 and 0.196, and the percentages of functional groups attached on the surface were found to be 6.80 and 5.92% for acid and base-catalyzed nanoparticles, respectively. The overall results suggest that acidic catalysis is a better approach for the synthesis of surface-modified or organofunctionalized silica nanoparticles.
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| 4. |
- Khan, Amir Sada, et al.
(författare)
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Efficient Conversion of Lignocellulosic Biomass to Levulinic Acid Using Acidic Ionic Liquids
- 2018
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Ingår i: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344. ; 181, s. 208-214
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Tidskriftsartikel (refereegranskat)abstract
- In the present research work, dicationic ionic liquids, containing 1,1-Bis(3-methylimidazolium-1-yl) butylene ([C4(Mim)2]) cation with counter anions [(2HSO4)(H2SO4)0], [(2HSO4)(H2SO4)2] and [(2HSO4)(H2SO4)4] were synthesised. ILs structures were confirmed using 1H NMR spectroscopy. Thermal stability, Hammett acidity, density and viscosity of ILs were determined. Various types of lignocellulosic biomass such as rubber wood, palm oil frond, bamboo and rice husk were converted into LA. Among the synthesized ionic liquids, [C4(Mim)2][(2HSO4)(H2SO4)4] showed higher % yield of LA up to 47.52 from bamboo biomass at 100 °C for 60 min, which is the better yield at low temperature and short time compared to previous reports. Surface morphology, surface functional groups and thermal stability of bamboo before and after conversion into LA were studied using SEM, FTIR and TGA analysis, respectively. This one-pot production of levulinic acid from agro-waste will open new opportunity for the conversion of sustainable biomass resources into valuable chemicals.
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